Prospective cohort study of children born to human immunodeficiency virus-infected mothers, 1985 through 1997: trends in the risk of vertical transmission, mortality and acquired immunodeficiency syndrome indicator diseases in the era before highly active antiretroviral therapy

Objectives. To assess changes in the risk of vertical transmission of HIV a nd changes in both mortality and morbidity among children in southern Conne cticut with HIV infection after the introduction of treatment of RN-infecte d pregnant women with antiretroviral drugs and of regimens to prevent or to treat AIDS indicator diseases in infected children. Methods, The risk of vertical transmission of HN, the rates of death and of AIDS indicator diseases and temporal trends in each were determined for ch ildren born in the first 5 years of a prospective, longitudinal cohort stud y (Period 1: December 1, 1985, through November 30, 1990) compared with tho se for children born during the latter 7 years of the study (Period 2: Dece mber 1, 1990, through November 30, 1997). Results. Of 347 infants enrolled, HIV infection status could be determined for 341; 44 (12.9%) were infected. The risk of vertical transmission declin ed from 20.7% among children born in Period 1 to 6.5% among children born i n period 2 (rate ratio, 3.2; 95% confidence interval, 1.7 to 6.0; P = 0.000 1), Of the 21 infected children who died, 11(52%) were less than or equal t o 18 months of age and 18 (86%) were less than or equal to 36 months of age at the times of death. Approximately one-fourth of infected children born during each period died at lr;18 months of age. Among those less than or eq ual to 36 months of age, 15 deaths occurred during 878 person months of obs ervation for those born in Period 1 compared with 3 deaths that occurred du ring 334 person months for those born in Period 2 (rate ratio, 1.9; 95% con fidence interval, 0.5 to 10.3; P = 0.45). Of the 44 children infected with HIV, 32 had one or more AIDS indicator diseases (a total of 67 episodes), 7 3% of which occurred when the children were less than or equal to 36 months of age. Among children born in Period 2, none developed Pneumocystis carin ii pneumonia and the rates of Mycobacterium avium complex disease and of wa sting syndrome declined, but the differences in rates of disease were not s tatistically significant. Conclusion. A substantial and statistically significant decline in the risk of vertical transmission of HIV-1 occurred during the 12-year study period . In contrast although there was a trend toward a decrease in mortality amo ng HIV-infected children less than or equal to 36 months of age and changes in the overall rates of AIDS indicator diseases among children born in Per iod 1 compared with Period 2, the differences were not statistically signif icant.